What does CTE really mean?

The recent information that former New England Patriots football player, Aaron Hernandez, was found to have evidence of Chronic Traumatic Encephalopathy (CTE) at autopsy has been followed by multiple opinions and at least one lawsuit.

Before drawing conclusions it is important to understand CTE and what the initial scientific studies really mean.

CTE is a diagnosis based on post-mortem findings of the brain. The diagnosis is actually a refinement of the previous findings of Dr. Harrison Martland, a medical examiner in Newark, N.J., who first described post-mortem changes in the brains of boxers in 1928.

A hallmark of CTE is the presence of tau protein, a substance that naturally occurs in nerve cells and appears to leak from the cells with repeated head trauma. The amount and distribution of the staining for tau coincide with the severity of CTE.

Although the predominant studies have been done on a group of deceased football players, many of whom have faced some life challenges, a direct causation between football and CTE has not been established.

One challenge with this condition is the fact that this can only be diagnosed after death. A study published last week in the journal PLOS ONE reports the identification of a potential biomarker to diagnose CTE in the living. The protein, known as CCL11, can be found in the spinal fluid of patients suspected of suffering from CTE.

It is important to note that no one has firmly linked the actions of someone with the CTE findings. The only thing we do know is that there are changes in the brain after repeated blows.

CTE research is ongoing and there is much to learn about chronic brain injury and its relation to sports. It is unfair and dangerous to make clinical assumptions that affect society and peoples’ lives at this early stage of investigation.

Dr. Alessi is a neurologist in Norwich and serves as an on-air contributor for ESPN. He is director of UConn NeuroSport and can be reached at agalessi@uchc.edu